import java.util.HashMap;
import java.util.Map;
import java.util.*;
public class lk2053 {
    public static void main(String[] args) {
        String s[]={"d","b","c","b","c","a"} ;
        int k=2;
        System.out.println(kthDistinct(s, k));
    }
    public static String kthDistinct(String[] arr, int k) {
        Map map = new HashMap<>();
        int n=arr.length;
        for(int i=0;i<n;i++){
            if(!map.containsKey(arr[i])){
                map.put(arr[i], true);
            }else map.put(arr[i], false);
        }
        for(int i=0;i<n;i++){
            if((boolean)map.get(arr[i])){
                k--;
                if(k==0){
                    return arr[i];
                }
            }
        }
        return "";
    }
}
